Sealing Ring Tools

What are sealing ring tools?

Sealing ring tools are hand tools designed to fit, remove, measure, and make O-rings and other sealing rings without damaging them. O-rings are easily nicked, cut, or stretched out of shape, and a damaged seal can fail soon after fitting. The right tools make seal changes quicker and safer, and help each seal last as long as it should.

A typical set of sealing ring tools covers five jobs:

• Removing old O-rings from grooves without scratching the groove
• Fitting new O-rings without twisting, stretching, or cutting them
• Measuring O-rings and grooves to find the right size
• Cutting and joining O-ring cord to make custom rings
• Identifying the material an O-Ring is made of

Good tools protect both the seal and the groove.

• Shaped tips and smooth edges let you lift an O-ring out of its groove without scoring the sealing surface underneath.
• Fitting aids guide the ring over threads, splines, and sharp edges, which would otherwise cut it.

Sealing ring tools are sized to handle a range of O-ring diameters, so one set can be used across many different jobs.

Why are sealing ring tools essential?

Many seal failures are caused during fitting rather than in service. Prising an O-ring out with a screwdriver can scratch the groove, creating a leak path that no new seal can fix. Forcing a new ring over a sharp thread can nick it, so it leaks or fails early. Using the right tools prevents this damage, reducing costly rework, repeat repairs, and downtime.

Measuring tools also prevent wrong-size seals being fitted, and splicing tools let engineers make custom rings on the spot instead of waiting for special sizes.

Typical users and applications include:

• Maintenance engineers and fitters
• Hydraulic and pneumatic repair
• Vehicle, plant, and agricultural workshops
• Pump, valve, and compressor servicing
• Plumbing and heating engineers
• Production and assembly lines
• Laboratory and instrument maintenance

The main types of sealing ring tools

• O-ring pick and hook sets - Thin tools with shaped tips, such as straight, angled, and hooked ends, for lifting O-rings out of grooves. Plastic or brass tips are gentler on soft or precision grooves than hardened steel.
• O-ring fitting and removal tools - Levers and fitting aids that help ease O-rings into and out of grooves, and over shafts and edges, without overstretching or twisting them.
• O-ring measuring tools - Measuring rods, sizing cones, and diameter tapes that make it quick to check the inside diameter of an O-ring or the size of a groove.
• O-ring cord cutters - Cutting tools that give a clean, square cut across O-ring cord, which is essential for a strong, smooth joint.
• O-ring splicing jigs - Jigs that hold the two cut ends of a cord in line while they are joined, so the finished ring is round and the joint is even.
• O-ring adhesives - Fast-setting adhesives designed for joining O-ring cord, often supplied in kits with a primer or cleaner.

How to choose the right sealing ring tools?

• Job type - Choose picks and fitting tools for maintenance and seal changes, measuring tools for identifying sizes, and cutters, jigs, and adhesive for making rings from cord.
• Tip material - Choose plastic or brass tipped tools for soft materials and precision grooves, and hardened steel for tougher jobs where groove damage is less of a concern.
• Size range - Check the tools suit the range of O-ring sizes and cord sections you work with.
• Sets or individual tools - A set gives a choice of shapes for different grooves, while single tools suit specific, repeated jobs.
• Compatibility - For splicing, check the cutter, jig, and adhesive suit the cord sizes and material you use.

Essential references and specialised ranges

How the numbering works:

Sealing ring tools do not follow a single numbering system. They are usually referenced by tool type and the range of sizes they suit, for example:

O-ring pick set, 4 piece = a set of four picks with different tip shapes

O-ring cord cutter, 1.6mm to 8mm = a cutter for cord sections from 1.6mm up to 8mm

Splicing jig, 1.6mm to 10mm = a jig that holds cord sections from 1.6mm up to 10mm

Check the size range and contents when choosing a tool or set.

Suffixes:

Sealing ring tools rarely carry standard suffixes. Where they do, they usually show the set size, tip material, or size range.

Suffix codes vary between manufacturers, so check the supplier’s catalogue for the exact meaning.

FAQ - All you need to know about sealing ring tools

Can I just use a screwdriver to remove an O-ring?

It is not recommended. A screwdriver can scratch the groove or cut the new O-ring, which can lead to leaks. A proper O-ring pick, ideally with a plastic or brass tip, lifts the ring out without damaging the groove.

How do I fit an O-ring over a thread without damaging it?

Cover the thread with a fitting sleeve, tape, or thin film, and lightly lubricate the ring. Roll it over the thread rather than dragging it, and avoid stretching it more than necessary.

How do I measure an O-ring?

Use a measuring rod or sizing cone to find the inside diameter, and callipers to measure the section. Measure the groove too, as an old ring may have stretched or flattened in use.

Why does O-ring cord need a special cutter?

A clean, square cut is needed for a strong joint. A knife can leave an angled or ragged end, which makes a weak joint and an uneven ring. A cord cutter gives a straight cut every time.

How do I use a splicing jig?

Cut the cord to length squarely, then place both ends in the jig so they meet in line. Apply the adhesive to the ends, close them together in the jig, and hold until the adhesive sets. Remove the ring and check the joint is smooth.

How do I choose the right size tool?

Check the size range of the tool against the O-rings and cord sections you work with most often. Sets with several tip shapes or sizes give the most flexibility for general maintenance.

When should sealing ring tools be replaced?

Replace tools when:

• Tips become bent, chipped, or burred, as they may scratch grooves or cut seals
• Cutter blades become blunt and leave ragged cuts
• Splicing jigs no longer hold the cord ends in line
• Measuring markings become worn and hard to read
• Adhesive has passed its use-by date or has thickened